Adding task grouping support with optional -group <group string> para…

…meter in the call to the shell. This will restrict workers to tasks with group field matching the supplied <group string>. Group param added as 4th parameter to QueuedTask::createJob(). Also adding reference field to sql and passed into the 5th parameter to QueuedTask::createJob() - intended to uniquely identify a task without having to fetch and unserialize the contents of the data field

config/sql/queue.php

@@ -35,6 +35,18 @@ function after($event = array()) {
 			'null' => true,
 			'default' => NULL
 		),
+		'group' => array(
+			'type' => 'string',
+			'length' => 255,
+			'null' => true,
+			'default' => NULL
+		),
+		'reference' => array(
+			'type' => 'string',
+			'length' => 255,
+			'null' => true,
+			'default' => NULL
+		),
 		'created' => array(
 			'type' => 'datetime',
 			'null' => false

models/queued_task.php

@@ -18,13 +18,17 @@ class QueuedTask extends AppModel {
 	 *
 	 * @param string $jobName QueueTask name
 	 * @param array $data any array
+	 * @param string $group Used to group similar QueuedTasks
+	 * @param string $reference any array
 	 * @return bool success
 	 */
-	public function createJob($jobName, $data, $notBefore = null) {
+	public function createJob($jobName, $data, $notBefore = null, $group = null, $reference = null) {
 
 		$data = array(
 			'jobtype' => $jobName,
-			'data' => serialize($data)
+			'data' => serialize($data),
+			'group' => $group,
+			'reference' => $reference,
 		);
 		if ($notBefore != null) {
 			$data['notbefore'] = date('Y-m-d H:i:s', strtotime($notBefore));
@@ -33,12 +37,14 @@ public function createJob($jobName, $data, $notBefore = null) {
 	}
 
 	/**
-	 * Look for a new job that can be processed with the current abilities.
+	 * Look for a new job that can be processed with the current abilities and
+   * from the specified group (or any if null).
 	 *
 	 * @param array $capabilities Available QueueWorkerTasks.
+   * @param string $group Request a job from this group, (from any group if null)
 	 * @return Array Taskdata.
 	 */
-	public function requestJob($capabilities) {
+	public function requestJob($capabilities, $group = null) {
 		$idlist = array();
 		$wasFetched = array();
 
@@ -58,6 +64,11 @@ public function requestJob($capabilities) {
 			),
 			'limit' => 3
 		);
+
+    if (!is_null($group)) {
+      $findConf['conditions']['group'] = $group;
+    }
+
 		// generate the task specific conditions.
 		foreach ($capabilities as $task) {
 			$tmp = array(

vendors/shells/queue.php

@@ -116,9 +116,13 @@ public function add() {
 	public function runworker() {
 		$exit = false;
 		$starttime = time();
+    $group = null;
+    if (isset($this->params['group']) && !empty($this->params['group'])) {
+      $group = $this->params['group'];
+    }
 		while (!$exit) {
 			$this->out('Looking for Job....');
-			$data = $this->QueuedTask->requestJob($this->getTaskConf());
+			$data = $this->QueuedTask->requestJob($this->getTaskConf(), $group);
 			if ($data != false) {
 				$this->out('Running Job of type "' . $data['jobtype'] . '"');
 				$taskname = 'queue_' . strtolower($data['jobtype']);